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Lactic acid has long been used in the food, chemical, textile, pharmaceutical and other industries. Ninety
percentage of the worldwide production of lactic acid is by microbial fermentation. Recently, there is an
increasing interest in the production of lactic acid, since it is a potential substrate for polylactic acid that
is biocompatible and can be used for medical purposes. Whey, which is a by-product of dairy industry,
contains approximately 5 % (w/v) lactose. Since whey has a high BOD content, it possesses serious
environmental problems. Whey lactose is a good substrate for lactic acid bacteria and can be used for
lactic acid fermentations. The lactic acid bacteria (LAB) were isolated from various sources such as curd,
idle batter, pickle and yoghurt and identified based on their morphological and biochemical
characteristics. Four potential isolates were screened out for the production of lactic acid. Immobilized
cells of LAB isolated from pickle was found to produce of maximum amount of Lactic acid (109.0g/L)
followed by LAB isolated from yoghurt (101.0 g/L), curd (88.0 g/L) and idle dough (80.0 g/L). This study
is focused on the production of lactic acid from whey by LAB immobilized in sodium alginate beads.
Lactose conversion to lactic acid was compared with immobilized and free cells. The immobilezed cells
showed potential to perform beneficially in the lactic acid fermentation industries, coupled with removal
of water pollutant, dairy whey.
Key words: Fermentation, Fermented Foods, Immobilization, Lactic acid, Lactic Acid Bacteria.